The assignment of a virtual FC server adapter to a physical FC port can be removed at any time. It should be noted, however, that the devices connected via the corresponding virtual FC client adapter (usually LUNs and/or tapes) on the client LPAR can then no longer be reached immediately. Access to tapes then immediately leads to an I/O error. When accessing connected LUNs, the behavior depends on whether multipathing is used (the AIXPCM Path Control Module is used by default with AIX) and whether paths to the affected LUNs are still available via other virtual FC client adapters.

As a concrete example, the following shows the procedure for removing the mapping for the virtual FC adapter fcs0 of the client LPAR aix22.

It should be checked whether all LUNs used have alternative paths via another virtual FC adapter:

aix22 # lspath
Enabled hdisk0 fscsi0
Enabled hdisk1   fscsi0
Enabled hdisk2   fscsi0
Enabled hdisk3   fscsi0
Enabled hdisk4   fscsi0
Enabled hdisk5   fscsi0
Enabled hdisk0 fscsi0
Enabled hdisk1   fscsi0
Enabled hdisk2   fscsi0
Enabled hdisk3   fscsi0
Enabled hdisk4   fscsi0
Enabled hdisk5   fscsi0
Enabled hdisk0 fscsi1
Enabled hdisk1   fscsi1
Enabled hdisk3   fscsi1
Enabled hdisk4   fscsi1
Enabled hdisk5   fscsi1
Enabled hdisk0 fscsi1
Enabled hdisk1   fscsi1
Enabled hdisk3   fscsi1
Enabled hdisk4   fscsi1
Enabled hdisk5   fscsi1
aix22 #

In the example output, all LUNs except hdisk2 have alternative paths via the second virtual FC adapter fcs1. The hdisk2 only has paths through fcs0:

aix22 # lspath -l hdisk2
Enabled hdisk2 fscsi0
Enabled hdisk2 fscsi0
aix22 #

This means, that if the mapping for fcs0 is removed, I/O to hdisk2 is no longer possible! However, the hdisk2 is not in use in our case:

aix22 # lspv|grep hdisk2
hdisk2          cafe000000000002                    None                        
aix22 #

Therefore we are permanently remove hdisk2 from the operating system:

aix22 # rmdev -dl hdisk2
hdisk2 deleted
aix22 #

All other LUNs have additional paths through fcs1 and therefore remain available. We remove the paths through fcs0, in order that they are no longer used:

aix22 # rmpath -dp fscsi0
paths Deleted
aix22 #

The associated virtual I/O server and the vfchost device for the virtual FC client adapter fcs0 can easily be found using the “vios lsnpiv” command:

$ vios lsnpiv ms03-vio1
NAME      SLOT  FC    FCLABEL  CLIENT        CLNTOS  VFCCLIENT  VFCSLOT  STATUS       PORTS
vfchost2  C5    fcs0  Fabric1  aix22(5)      AIX     fcs0       C10      LOGGED_IN      7
vfchost3  C125  fcs0  Fabric1  aixsap01(9)   AIX     fcs0       C10      LOGGED_IN      7
vfchost4  C181  fcs0  Fabric1  aixdbp02(11)  AIX     fcs0       C10      LOGGED_IN      5
vfchost5  C182  fcs0  Fabric1  aixdbi02(13)  AIX     fcs0       C10      LOGGED_IN      5
vfchost6  C38   fcs0  Fabric1  aix22(5)      AIX     fcs2       C11      LOGGED_IN      1
$

The assignment can now be removed, using the “vios vfcunmap” command (unmap virtual FC adapter):

$ vios vfcunmap ms03-vio1 vfchost2
vfchost2 unmapped
$

Instead of the device name for the vfchost adapter, as with mappings, the slot number or a unique suffix of the physical location code can be specified as well.